This invention relates to a power control apparatus provided on a power supply line so as to effect the interruption of power supply and so on.
FIGS. 16 to 18 show one conventional power control apparatus of the type described (serving as a power interrupting apparatus) disclosed in JP-A-11-219631. As shown in FIGS. 16 to 18, the power interrupting apparatus 100 comprises a casing 101, made of a synthetic resin, a motor 102, fixedly mounted on this casing 101, a worn gear 103, fixedly mounted on a rotation shaft 102a of the motor 102, a worn wheel portion 104 disposed in mesh with this worm gear 103, a pivotal (swinging) terminal 105 (serving as a moving terminal), pivotally mounted at one side portion thereof on the casing 101, a pair of opposed fixed terminals 106 and 107, disposed near respectively to upper and lower sides of a path of pivotal movement of the pivotal terminal 105, and resilient contact elements 108 and 109 mounted respectively on inner surfaces of the fixed terminals 106 and 107.
The pivotal terminal 105 has a conducting portion 110 and an insulating portion 111 juxtaposed to each other in a direction of pivotal movement of this pivotal terminal. One of the two fixed terminals 106 and 107 is electrically connected to a power source while the other is electrically connected to a load.
In the above construction, the motor 102 is driven to pivotally move the pivotal terminal 105, and when the conducting portion 110 of the pivotal terminal 105 is brought into a swinging position where this conducting portion 110 is inserted between the pair of fixed terminals 106 and 107 as shown in FIG. 16, the pair of fixed terminals 106 and 107 are electrically connected together through the pivotal terminal 105, thus achieving an electrically-conducting condition.
When the insulating portion 111 of the pivotal terminal 105 is brought into the swinging position where this insulating portion 111 is inserted between the pair of fixed terminals 106 and 107 as shown in FIG. 17, the pair of fixed terminals 106 and 107 are electrically disconnected from each other through the pivotal terminal 105, thus achieving an interrupting condition.
In the above conventional power interrupting apparatus 100, however, the pivotal terminal 105 is provided as the moving terminal, and the upper and lower surfaces of this pivotal terminal 105, disposed in the same direction as the direction of rotation of this pivotal terminal, serve as contact surfaces for the pair of fixed terminals 106 and 107. Therefore, there was encountered a problem that a space, larger than a space for mounting the pivotal terminal 105, need to be secured as a space for moving the pivotal terminal 105, and this was one of the causes for the increased size of the apparatus.
In the above conventional power interrupting apparatus 100, however, the conducting portion 110 of the pivotal terminal 105 is slidingly inserted between the resilient contact elements 108 and 109 (fixedly secured at their opposite ends to the pair of fixed terminals 106 and 107, respectively), and therefore is contacted with these resilient contact elements. Therefore, if the gap between the pair of fixed terminals 106 and 107 varies to decrease even slightly, the sliding insertion of the pivotal terminal 105 would become extremely difficult, and if the gap between the pair of fixed terminals 106 and 107 varies to increase even slightly, the pressure of contact between the resilient contact elements 108 and 109 and the conducting portion 110, as well as the area of contact therebetween, would extremely decrease. Therefore, this construction is not suited for the type of power interrupting apparatus to be provided on a power supply line for flowing a large current therethrough.
Therefore, this invention has been made in order to solve the above problem, and an object of the invention is to provide a power control apparatus in which a space for moving a moving terminal is available merely by securing a space for mounting this moving terminal, and the overall size of the apparatus can be reduced. Further, an object of the invention is to provide a power control apparatus which can be suitably used for a power supply line of a large current.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) A power control apparatus comprising:
a rotating terminal including a circumferential outer peripheral surface, and having electrically conductive areas and non-electrically conductive areas alternately arranged on the outer peripheral surface in a circumferential direction thereof; and
a pair of fixed terminals fixed and disposed outwardly of a path of rotation of the outer peripheral surface,
wherein the pair of fixed terminals is switched between an electrically conducting condition in which the pair of fixed terminals are electrically connected together through the rotating terminal, and an interrupting condition in which the electrical connection between the pair of fixed terminals through the rotating terminal is interrupted in accordance with a rotating position of the rotating terminal.
(2) The power control apparatus according to (1), wherein the rotating terminal is rotated by a driving force of a motor.
(3) The power control apparatus according to (2) further comprising a controller for controlling the driving of the motor so as to control the electrical connection between the pair of fixed terminals and the interruption of the electrical connection.
(4) The power control apparatus according to (3) further comprising a manual switch for feeding a power interrupting instruction to the controller.
(5) The power control apparatus according to (1) further comprising a current sensor for detecting a current level of a power supply line which can be made conductive and can be interrupted by the rotation of the rotating terminal.
(6) The power control apparatus according to (1), wherein the pair of electrically conductive areas are symmetric with respect to an axis of rotation of the rotating terminal, and the pair of non-electrically conductive areas are symmetric with respect to the axis thereof.
(7) The power control apparatus according to (1), wherein a multi-contact spring member is provided at the electrically conductive areas for electrically connecting the pair of fixed terminals.
(8) The power control apparatus according to (7), wherein the multi-contact spring member includes a rail member extending between the electrically conductive areas, and a plurality of resilient contact springs projecting outwardly from the rail member at the electrically conductive areas, which is brought into contact with the pair of fixed terminal in the electrically conducting condition.
(9) The power control apparatus according to (8), wherein the plurality of contact spring project in an inclined manner so as to extend toward a direction opposite to a rotating direction of the rotating terminal.
(10) The power control apparatus according to (1), wherein
an electrically-conductive contact spring is provided at the outer peripheral surface of the rotating terminal, and the contact spring is fixed at one end thereof to the outer peripheral surface while the other end thereof serving as a free end projects from the outer peripheral surface, and
each of the pair of fixed terminal includes a contact surface in which the contact spring can be brought into contact with the contact surface in a resiliently-deformed condition.
(11) The power control apparatus according to (10), wherein insulating frames are disposed adjacent to the outer peripheral surface of the rotating terminal, and are provided respectively at other regions than the regions where the pair of fixed terminals are provided, and the insulating frames have respective contact surfaces, and the contact surfaces of the insulating frames and the contact surfaces of the pair of fixed terminal are disposed on a common circle, and jointly form a substantially perfect circumferential surface.
(12) The power control apparatus according to (10), wherein the electrically-conductive areas are formed respectively of an electrically-conducting member at an outer peripheral surface, and the non-electrically conducting areas are formed respectively of isolation portions at outer peripheral surfaces.
(13) The power control apparatus according to (1), wherein sacrifice terminal portions are provided respectively upstream of the contact surfaces of the pair of fixed terminals in a rotating direction of the rotating terminal.
(14) The power control apparatus according to (10), wherein a plurality of the contact springs are provided at the outer peripheral surface of the rotating terminal.
(15) the power control apparatus according to (10), wherein the contact spring is inclined in such a manner that the free end of the contact spring is disposed downstream of fixed end of the contact spring in the rotating direction of the rotating terminal.
(16) The power control apparatus according to (12), wherein
the rotating terminal comprises the electrically conducting member, and insulating resin caps attached to the electrically conducting member, and
the resin cap includes a spring receiving groove in which a rail member, interconnecting the contact springs, is received and fixed held.
(17) The power control apparatus according to (1), wherein
electrically-conductive contact spring are provided at the peripheral surfaces of the fixed terminals, and each contact spring is fixed at its one end to the peripheral surface while the other end thereof serving as a free end projects from the outer peripheral surface, and
the rotating terminal has a contact surface, and the contact spring can be brought into contact with the contact surface in a resiliently-deformed condition.